A computer network typically consists of many different entities. A first type of entity is an end station. An end station is a computer from which message traffic is originated, known as a source node, and also at which message traffic is received, known as a destination node. A second type of entity is an intermediate node. An intermediate node receives message traffic and forwards the messages onto a further network to move the message on to the desired destination station. Typically, an intermediate node receives messages from either end stations or from other intermediate nodes, and the intermediate node is connected to several networks so that the intermediate node makes a decision as to which network the message is to be forwarded. Typically, intermediate nodes are point-to-point switches, routers, bridges, etc.
In order for a message to be forwarded to a first intermediate node by either an end station or another intermediate node, the first intermediate node must have an address. The address is, typically, a binary number, that is a series of "1" and "0" characters. The address of every addressable entity in the network must be unique in order for a message to be delivered to the right place.
The binary address is usually divided into fields, and the fields are typically represented in hexadecimal notation for ease of human consideration. At least one field of the address of an entity is, typically, built into the apparatus of the entity by the manufacturer of the entity by placing a unique address in a read only non-volatile memory at the factory when the entity was manufactured. The non-volatile memory is typically a semiconductor Read Only Memory, or ROM. The entity is said to contain an End Station Identifier, or ESI in the ROM. When the entity is an intermediate node, the ROM in the intermediate node is said to contain an ESI for that intermediate node. Typically, the address stored in the non-volatile read only memory in an entity is referred to as the "physical address" of the entity. In other words, the ESI may be the physical address.
The Institute of Electrical and Electronic Engineers, hereinafter IEEE, performs a service of assisting in keeping track of physical addresses of addressable network entities. The IEEE assigns blocks of addresses to manufacturers. The manufacturer then assigns one address from its assigned block of addresses to each addressable entity manufactured by writing the address into a non-volatile read only memory installed in the entity.
For example, a network may be designed in accordance with the specifications promulgated as Asynchronous Transfer Mode, or ATM, networks, by the ATM Forum. The ATM Forum is a voluntary association of manufacturers and other interested parties, and the specifications are promulgated by agreement of the members of the association. The ATM technique, as it is known today, is disclosed in the textbook, "ATM User-Network Interface Specification, Version 3.0", Prentice Hall, Englewood Cliffs, N.J., 1993, all disclosures of which are incorporated herein by reference.
In the ATM technique of computer network design, there are at least two types of entities defined. The first type of entity is an end station, and the second type of entity is an intermediate node referred to as an "ATM Switch". An ATM switch is a point to point switch. Each end station is connected to one ATM Switch. Several ATM Switches may be connected to other ATM Switches. The point to point character of the ATM Switches permits appropriate connections to be made in each ATM Switch to connect any two desired end stations together for the transfer of message traffic.
When ATM Switches are connected into a network, it is desirable to assign an address to each in a manner which creates a hierarchical network having Peer Groups at different levels of the hierarchy. Creating such a hierarchical network requires adding bytes of address to the ESI of each ATM Switch. The added bytes define the hierarchical construction. In accordance with specifications of the ATM Forum, the added bytes are used as prefixes of the ESI of the switch.
Human intervention is required to add the hierarchical bytes to the ESI of an ATM Switch. Unfortunately, human intervention is slow, costly, and prone to error.
It is desirable to have an automatic method of assigning addresses to intermediate nodes in a computer network so as to create a desired addressing environment.